[Effect of electroacupuncture stimulation of "Neiguan" (PC 6) on expression of alpha- and beta-subunit proteins of voltage-gated sodium channels in rats with myocardial ischemia].

OBJECTIVE

To observe the effect of electroacupuncture (EA) stimulation of "Neiguan" (PC 6) on expression of sodium (Nav) channel α-subunit 1.5 and Nav β-subunits β 1-β 4 (the known myocardial sodium channel proteins) in acute myocardial ischemia (AMI) rats so as to explore its mechanisms underlying protection of ischemic myocardium.

METHODS

Sixty SD male rats were randomly divided into normal control, AMI model, Neiguan (PC 6), Lieque (LU 7) and non-acupoint groups. The AMI model was established by intravenous injection of Isoprenaline (85 mg/kg) once daily for 2 days. Myocardial Nav 1.5 and Nav β 1, β 2, β 3, β 4 protein expression levels were detected by Western blot.

RESULTS

In comparison with the control group, myocardial Nav 1.5, β 1, β 2, β 3 and β 4 protein expression levels were significantly down-regulated in the AMI model group (P<0.01). After EA stimulation, compared with the model group, the expression levels of Nav 1.5, Nav β 1, β 2, β 3 and β 4 protein expression levels were significantly up-regulated in the Neiguang (PC 6) and Lieque (LU 7) groups (P<0.01) rather than in the non-acupoint group (P>0.05). There was no statistical significance between the Neiguan (PC 6) and Lieque (LU 7) groups in β 4 protein expression level (P>0.05).

CONCLUSION

EA stimulation of both PC 6 and LU 7 can significantly reverse AMI-induced down-regulation of myocardial Nav 1.5, β 1, β 2, β 3 and β 4 protein expression levels in AMI rats, which might contribute to its function in improving AMI by reducing calcium overload.